瓣叶修复系统的体外流体动力学性能评估

目的 针对二尖瓣反流疾病的治疗需求,该研究设计了一种瓣叶修复系统,并评估其流体动力学性能。方法 设计二尖瓣反流模型,将瓣叶修复系统安装到反流模型上,分别进行脉动流试验及稳态流泄漏试验。结果 脉动流试验结果显示,在不同心排血量及不同反向压力下,瓣叶修复系统植入后的反流量较植入前降低,且植入后的平均跨瓣压差小于5 mmHg;稳态流泄漏试验结果显示,随着反向压力的升高,瓣叶修复系统植入后的泄漏量也随之增加。结论 所研制的瓣叶修复系统具有良好的流体动力学性能,预示着其治疗二尖瓣反流的可行性。

一种新型介入瓣膜脉动流性能的初步研究

本文对一种国产新型介入瓣膜(HVPMIT)的体外脉动流性能进行了初步评价,并就该方法对HVPMIT的适用性进行了初步探索。试验中以国产HVPMIT为试验样品、进口的常规生物瓣为对照样品,根据ISO5840-2005和GB 12279-2008标准列出的方法,采用人工心脏瓣膜脉动流测试仪测定了试样的脉动流参数(包括平均跨瓣压差、返流百分比和有效开口面积)。结果显示,在模拟心输出量为5L/min时,HVPMIT的返流百分比高达13%,显著高于对照瓣,显示其发生了瓣周漏。进一步分析可以发现因为HVPMIT在植入体内时不需缝合,因此在HVPMIT支架外侧没有缝合环。当将HVPMIT夹持在试验仪器上时夹持垫片和HVPMIT支架间有明显缝隙,所以导致瓣周漏的发生。这说明,HVPMIT在外形、结构、在心脏上的固定方式、临床的手术方法等方面和传统的心脏瓣膜有明显的区别。必须根据其自身的特点,设计和建立适用的检测方法来科学客观地评价HVPMIT的性能。

Experimental study on pressure fluctuation characteristics of slug flow in horizontal curved tubes

In order to study the pressure characteristics of slug flow in horizontal curved tubes,two kinds of curved tubes with central angle 45° and 90° respectively are studied,of which are with 0. 5m circumference and 26 mm inner diameter are used. When the superficial liquid velocity or the superficial gas velocity is constant,the pressure fluctuations and the probability distribution of the average velocity of slug flow are clear for all of the five experimental conditions. The results of experiment show that the pressure characteristics of slug flow in curved tubes have periodic fluctuations. With the rise of central angle,the period of pressure fluctuation is more obvious. The system pressure of the slug flow increases with the increasing of superficial liquid/gas velocity. Meanwhile,the probability distribution of pressure signal shows regularity,such as unimodal,bimodal or multimodal.